Scientifically, is there any difference in sound quality between a used CD and a new CD? There are CD cleaning products out there that claim that sound quality will improve if you clean your CDs. My understanding is that a bit is a bit, and there will be no difference in sound quality between a used CD and a new one. Even a scratched, but fully playable CD will sound as good as new. I'm not referring to skipping, pops or clicks. I'm referring to the bass, highs, mids, dynamic range sound quality of the CD. Thanks.